Answer:
1.
Dalton's theory (early 19th century): Atoms were considered indivisible and indestructible.
Modern atomic theory: Atoms are divisible into subatomic particles - protons, neutrons, and electrons.
2.
Dalton: All atoms of a given element are identical in mass and properties.
Modern theory: Isotopes exist, meaning atoms of the same element can have different masses due to varying numbers of neutrons.
3.
Dalton: Atoms were thought to be solid, indivisible spheres.
Modern theory: Describes the atom as having a nucleus containing protons and neutrons, with electrons in orbit around the nucleus.
4.
Dalton: Conservation of mass was a fundamental principle.
Modern theory: Mass is conserved in chemical reactions, but mass can be converted to energy (E=mc²) according to Einstein's theory of relativity.
5.
Dalton: Elements combine in definite ratios to form compounds.
Modern theory: This law still holds true, but with a deeper understanding of the actual masses and structures involved.
6.
Dalton: Atomic masses were assigned without accurate measurements.
Modern theory: Atomic masses are measured with precision using mass spectrometry, reflecting the average mass of isotopes in a naturally occurring sample.
7.
Dalton: Described the behavior of gases based on the assumption of indivisible atoms.
Modern theory: Explains gas behavior using kinetic molecular theory, considering the motion of particles within the gas.
8.
Dalton: Explained chemical reactions as the rearrangement of atoms.
Modern theory: Describes chemical reactions as involving the rearrangement of atoms and the breaking and forming of chemical bonds.
9.
Dalton: Did not have a clear understanding of Avogadro's hypothesis.
Modern theory: Avogadro's hypothesis states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.
10.
Dalton: Did not have knowledge of quantum mechanics.
Modern theory: Quantum mechanics provides a detailed understanding of the behavior of subatomic particles and their interactions.